Benchmarks performed with NWChem

This page contains a suite of benchmarks performed with NWChem. The benchmarks include a variety of computational chemistry methods on a variety of high performance computing platforms. The list of benchmarks available will evolve continuously as new data becomes available. If you have benchmark information you would like to add for your computing system, please contact one of the developers.

Hybrid density functional calculation on the C240 Buckyball

Performance of the Gaussian basis set DFT module in NWChem. This calculation involved performing a PBE0 calculation (in direct mode) on the on C240 system with the 6-31G* basis set (3600 basis functions) without symmetry. These calculations were performed on the Cascade supercomputer located at PNNL. The input file is available.

AIMD Parallel timings for +122H2O. These calculations were performed on the Franklin Cray-XT4 computer system at NERSC.

AIMD and AIMD/MM Parallel Timings for Zn2 + +64H2O (unit cell parameters SC=12.4 Angs. and cutoff energy =100Ry). These calculations were performed on the Chinook HP computer system at MSCF EMSL, PNNL.

Exact exchange timings – 80 atom cell of hematite (cutoff energy=100Ry). These calculations were performed on the Franklin Cray-XT4 computer system at NERSC.

Exact exchange timings – 576 atom cell of water (cutoff energy=100Ry). These calculations were performed on the Hopper Cray-XE6 computer system at NERSC.

Parallel performance of the CR-EOMCCSD(T) method (triples part)

An example of the scalability of the triples part of the CR-EOMCCSD(T) approach for Green Fluorescent Protein Chromophore (GFPC)
described by cc-pVTZ basis set (648 basis functions) as obtained from NWChem. Timings were determined from calculations on the Franklin Cray-XT4 computer system at NERSC.
See the input file for details.

In collaboration with Dr. Jiri Pittner's group from Heyrovsky Institute of Physical Chemistry implementations of two variants of state-specific MRCC approaches
have been developed. During his internship at PNNL Jirka Brabec, using novel processor-group-based algorithms, implemented Brillouin-Wigner and Mukherjee MRCC models with singles and doubles. The scalabililty tests for the Brillouin-Wigner MRCCSD approach have been performed on Jaguar XT5 system at ORNL for β-carotene in 6-31 basis set (472 orbitals, 216 correlated electrons, 20 reference functions; see J.Brabec, J. Pittner, H.J.J. van Dam, E. Aprà, K. Kowalski, JCTC
2012, 8(2), pp 487–497). Currently, PNNL postdoctoral fellow Dr. Kiran Bhaskaran Nair is developing perturbative MRCCSD(T) approaches, which accounts for the effect of triple excitations.

Scaling of the triples part of the BW-MRCCSD(T) method for β-carotene in 6-31 basis set (JCP 137, 094112 (2012)). The scalability tests of the
BW-MRCCSD(T) implementation of NWChem have been performed on the Jaguar Cray-XK6 computer system of the National Center for Computational Sciences at Oak Ridge National Laboratory.

Timings of CCSD/EOMCCSD for the oligoporphyrin dimer

CCSD/EOMCCSD timings for oligoporphyrin dimer (942 basis functions, 270 correlated electrons, D2h symmetry, excited-state calculations were
performed for state of b1g symmetry, in all test calculation convergence threshold was relaxed, 1024 cores were used). See the input file for details.

Non-iterative part of the CCSD(T) approach: Comparing Xeon Phi and NVidia K20X performance

Wall time to solution (in seconds) of non-iterative triples part of the single-reference CCSD(T) approach for the pentacene molecule using Intel MIC and Nvidia GPU implementations.
Tests were performed using 96 compute nodes on the Cascade system at EMSL (Intel® Xeon™ Phi 5110P) and Titan system at ORNL (NVIDIA Tesla® K20X).

Current developments for high accuracy: alternative task schedulers (ATS)

Currently various development efforts are underway for high accuracy methods that will be available in future releases of NWChem. The examples below shows the first results of the performance of the triples part of Reg-CCSD(T) on GPGPUs (left two examples) and of using alternative task schedules for the iterative CCSD and EOMCCSD.

Scalability of the triples part of the Reg-CCSD(T) approach for Spiro cation described by the Sadlej's TZ basis set (POL1).

Speedup of GPU over CPU of the (T) part of the (T) part of the Reg-CCSD(T) approach as a function of the tile size for the uracil molecule.

The impact of the tilesize on the CCSD(ATS) timings: All tests have been performed for uracil trimer (6-31G* basis set; all core electrons frozen)
on Hopper using 25 nodes (600 cores). One can observe almost 10-fold speedup of the CCSD(ATS) code for tilesize=40 compared to standard TCE CCSD implementation
using tilesize=12.